Foreground object locating device

ABSTRACT

A foreground object locating device comprising a laser light generator for projecting in a desired forward direction a laser light consisting of a series of pulses having a preset repetitive period, and a color television mechanism for receiving optical images focused on optical lens in response to a pulsated echo laser light reflected from various objects present in the direction in which the pulsated laser light is initially projected by the laser light generator and displaying on the screen video images corresponding to the optical images in different colors distinguishing the video images of the previously classified distance zones.

O United States Patent 5] 3,649,124 Takaoka et al. [4 1 Mar. 14, 1972[54] FOREGROUND OBJECT LOCATING 3,369,231 2/1968 Fora] ..343/7.9 DEVICE3,463,588 8/1969 Meyerand, Jr. et al, .....356/5 3,305,633 2/1967Chernoch ..356/5 [7 Inventors: Takashi Takaoka, Kawasaki-Shh Saiichi3,004,254 10/1961 Steinberg et al .343/5 CD 911525 15 iY k bama v-wt rYi 1 w Kamakurashli of Japan Primary Examiner Rodney D. Bennett, Jr. 73Assignee: Tokyo Shibaura Electric co., Ltd., Assistant Examiner-SBuczinski Kawasakbshi, Japan AttorneyGeorge B. Oujevolk [22] Filed: DEC.1, 1969 57 ABSTRACT [211 App! 881318 A foreground object locating devicecomprising a laser light generator for projecting in a desired forwarddirection a laser [30] Foreign Application Priority Data lightconsisting of a series of pulses having a preset repetitive period, anda color television mechanism for receiving optical Dec. 5, 1968 Japan..43/88808 images focused on optical lens in response to a pulsated echolaser light reflected from various objects present in the [52] Cl "fg figlgf Z I direction in which the pulsated laser light is initiallyprojected 5 Int. Cl 6 by the laser light generator and displaying on thescreen video 58] Field 5 13 CD images corresponding to the opticalimages in different colors 3 TV 178/65 distinguishing the video imagesof the previously classified distance zones. [56] References C1ted 9Claims, 19 Drawing Figures UNITED STATES PATENTS I 3,380,358 4/1968Neumann ......356/5 PULSATED LASER I I LIGHT GENERATING 27 {5 MEANS i426 FIRST 5 6 f LASER LIGHT PULSE SIGNAL 28 ,5 EXN :JMONITOR GENERATING IO i 2 MEANS I MEANS I l Q1 SECOND IMAGE I i I OPTICAL INTENSIFIER"TEIEE6ISION I NL CAMERA MEAN MONITOR CIRCUIT m I l- 22 20 W I t AllPOWER 3 M2 Q2 19 '8 E M5 i, Q3 GATE PULSE GENERATING V 114 and MEANSPatented March 14, 1972 4 Sheets-Sheet 2 F i G. 2 A KPI HKPZ KPH (PIFIG. 28

FIG. 2C

FIG. 2D FIG. 2E

FIG. 2F FIG. 26

SAW WAVE MONO-STABLE GENERATOR MUIJIVIBRATOR 33b MONO-STABLEMULTIVIBRATOR I MONO-STABLE MULTIVIBRATOR FIG. 5

I To 6% 76 FOREGROUND OBJECT LOCATING DEVICE The present inventionrelates to a foreground object locating device and more particularly toa type. of such device which can locate, by means of laser light,movable objects traveling ahead of shipping, rolling stock or aircraftor other stationary objects such as rocks, wharves or hills lying aheadof the aforementioned transport media in the form of imagesdistinguished by colors according to the relative positions of theseobjects with respect to said transport media or a predeterminedclassification of distance therebetween.

The foreground object locating devices heretofore practically appliedinclude those based on the technology of television or radarobservation. However, the former type using television technology onlyindicates the contour offoreground objects in a plan view and fails todetect the distance up to said objects. On the other hand, the lattertype involving radar technology can indeed detect the distance up to atarget object, but presents difficulties in exactly defining its generaloutline. Accordingly, accurate determination ofthe shape ofa foregroundobject, as well as of a distance thereto, requires a joint use of saidtwo types of devices. However, an apparatus involving such a combinationhas generally been of an extremely complicated arrangement, accompaniedwith troublesome operation and presented difficulties in locatingobjects lying at various points according to an exact classification ofzones of distance and reproducing their images in a three-dimensionalform. The aforesaid combination apparatus had a drawback in that itsability of stereographically representing three-dimensional objectsaccording to such classification prominently decreased under theconditions where there was only available a limited field of vision, forexample, at night time, or in dense fog.

Accordingly, there have often occurred accidents where a ship sailing inweather that only permitted a narrow range of view struck againstanother vessel, wharf or rock lying ahead of its course or an airplaneflying under similar unfavorable weather conditions ran into anotherplane or a hillside located in front of its course.

The present invention has been accomplished in view of theabove-mentioned circumstances and is intended to provide a type offoreground object locating device which can be easily operated due toits relatively simple arrangement and indicate the contours of movableor stationary foreground objects, together with distances thereto, inthe form distinguished by colors according to a predeterminedclassification of zones of distance up to said objects, therebypreventing at all times the occurrence of an accident where theaforementioned transport media such as shipping, rolling stock oraircraft collide with other objects.

Generally speaking, the present invention provides for an improvement ina foreground object locating device having a pulse generation circuitfor generating a series of pulses with a preset repetitive period, alaser light generator for generating a laser light consisting of aseries of pulses having the same repetitive period when triggered byoutput pulses from said pulse generation circuit, first and secondoptical means for projecting the output pulsated laser light from thelaser light generator in a predetermined direction and for receiving apulsated echo laser light reflected from various foreground objectspresent in the spotlighted direction and focusing optical imagescorresponding to the pulsated echo laser light, and, a color televisionmechanism for receiving the optical images and displaying on a videoscreen images corresponding to the respective optical imagesrepresenting said objects present in previously classified distancezones distinguished by different colors. The improvement generallycomprises that said pulse generation circuit includes a pulse generatorfor generating a series of pulses having the same repetitive period asthat of the series of laser light pulses generated by said laser lightgenerator. A saw wave generator is coupled to said pulse generator forreceiving output pulses from said pulse generator to generate saw wavesignals having substantially the same period as that which is covered bya set of pulses having the same number as that of the colors used incolor television presentation. A plurality of juxtaposed clippers aredisposed for receiving output saw wave signals from said saw wavegenerator, the bias points of said clippers being defined at a pluralposition having different potentials on the leading edge of each of saidsaw wave signals which are spaced from each other by a distancecorresponding to substantially the same time interval as the repetitiveperiod of said series laser light pulses. A plurality of differentiationcircuits are connected in series to the output terminal of each of saidclippers.

This invention can be more fully understood from the following detaileddescription when taken in connection with reference to the accompanyingdrawings, in which:

FIG. 1 is a schematic block diagram of a foreground object locatingdevice according to an embodiment of the present invention;

FIGS. 2A to 26 represent the wave-forms used in the practical operationof the various circuit sections shown in FIG. 1;

FIG. 3 indicates a preferred practical circuit arrangement of aforeground object locating device according to said embodiment showingfurther details of the circuit of FIG. 1-;

FIGS. 4A to 41 show the wave-forms used in the practical operation ofthe various circuit sections of FIG. 3; and

FIG. 5 illustrates a practical modification of the pulse generationcircuit included in the circuit arrangement of FIG. 3.

For convenience, there will now be described a concrete case where thereis mounted on a ship sailing on the sea a foreground object locatingdevice according to an embodiment of the present invention. In thiscase, the predetermined range of distance ahead of the scheduled courseof said ship is separated into three successive zones. Each such Zone ismade to correspond to the duration of one field scanning operation ofthe later described image intensifier camera means and there areconducted in succession the durations of three field scanning operationsconstituting one frame so as to distinguish projected images by colorscorresponding to each zone of said distance, thereby determining whetheror'not there lies ahead of said scheduled course of the traveling shipany movable object, for example, another ship, or any stationary object,for example, rock, or wharf. Referring to FIG. 1, the whole range ofdistance to be observed is marked by four boundaries I to 1,, namely,separated into three zones, i.e., a first zone Al,( =I I,), a secondzone Al (=I I and a third zone A! -,(=l -l A foreground object locatingdevice according to the present invention represented by general numeral11 comprises a pulsated laser light generator 13 supplied in operationwith driving power by a power source 12. In said generator 13, threeadjacent pulses from the later described pulse generation circuit 14 aregrouped into one set (corresponding to said one frame) so as to besynchronized with each duration of the field scanning operation of thelater described image intensifier camera means 20 and triggered by aseries of pulses P,, I and P intermittently generated, as shown in FIG.2A, for each preset repetitive period Tr, and modulated in pulse width,thereby projecting, as shown in FIG. 28, a laser light comprising aseries of pulses PL,, l' L and PL respectively generated with apredetermined time delay Td corresponding to each of the aforesaidseries of pulses P P and P Accordingly. the repetitive period of each ofsaid series of pulses PL,, PL? and PL of said laser light has the sameperiod Tr as that of each of said series of pulses P P and P generatedby the aforesaid pulse generation circuit 14. The delay time Tdrepresented by the length of time consumed between generation of aseries of pulses P,, P and P by said pulse generation circuit 14 andprojection of a corresponding pulsated laser light comprising a seriesof pulses PL PL; and FL; by said laser light generator 13 is extremelysmall as compared with other lengths of time required for the subjectforeground object locating device to process signals. In the followingdescription, therefore, said time delay Td is disregarded, and pulsesfrom the pulse generation circuit 14 are deemed to be generated at thesame time as a pulsated laser light from the laser light generator 13.

lOlO27 .A laser light comprising a series of pulses PL,, PL; and PL;which is generated by said laser light generator 13 is projected in thepredetermined direction indicated by the arrow 16 of FIG. I in the formhaving a desired coverage through a first optical means consisting of aconvex or concave lens or a suitable combination thereof.

On the other hand, a series of pulses P P and I generated by the pulsegeneration circuit I4 are supplied as trigger signals to the laser lightgenerator I3 and also to a pulse delay circuit 17. In a special case,where the time delay Td is expected to be too great to be disregarded.there is provided a laser light monitor means 29 for converting part ofthe light generated by the laser light generator I3 to an electricalsignal by photodetector. Outputs from the monitor 29 are directly sentto the pulse delay circuit 17 instead of supplying outputs from thepulse generation circuit 14 to said pulse delay circuit l7. Accordingly,the series of pulses PL PL and PL of a laser light shown in FIG. 2Bwhich are pro ected by the laser light generator 13 through the firstoptical means IS in the predetermined direction are converted. as shownin FIG. 2C, mm a group of three delay pulses P P and P having first,second and third time delays l and i respectively which represent thelengths of time required for the aforesaid pulses lPL PL and PL, of alaser light to travel back and forth between the foremost boundaries 1,,l and i of the first, second and third zones of distance 31,, A1 and A1These three delay pulses P P, and P, are conducted to the sucseedinggate pulse generator 18 and further converted, as shown in FIG. 2D, intofirst, second and third gate pulses P P and P having time widths Al A!and A! corresponding to the aforesaid three zones ofdistance A1 A1 andA1 respectively. It will be apparent that the time delays t and i andtime widths Ar Ar and At of the first, second and third pulses P P and Pconstituting one group are defined in such a manner that time delay I,IS determined by the starting boundary I of the nearest zone Al,included in the predetermined range of distance to be observed which isdefined between the boundaries 1 and 1 and other time delays aredetermined so as to satisfy the relationships oft r A 1 Tr, t 3.1-, Tr.and r r t A t s Tr. If, in this case, the light velocity is designatedas C at which a laser light is pro ected by the laser light generator 13through the first optical means 15, then there will result the followingequations:

Each group of gate pulses P P and P shown in FIG. 2D which are derivedout of the gate pulse generator 18 is impressed on the image intensifiercamera means previously brought to a waiting state by a power source 19so as to suecessively render said camera means 20 operable for imagepickup only for a length of time corresponding to the time width of eachgate pulse. When a laser light comprising a series of pulses PL PL; andPL shown in FIG. 2B generated by the laser light generator I3synchronized with the time at which the image intensifier camera means20 is made operable for image pickup is projected on to foregroundobjects such as other ships than that which carries a locating device.rocks or wharves and then brought back in the form of an echo laserlight to said image intensifier camera means 20 through a second opticalmeans 22 having substantially the same arrangement as the first opticalmeans I5, there will be derived but of the output terminal of saidcamera means 20 video signals corresponding to optical images focused onthe sound optical means 22 according to the pulses of said echo laserlight. When the video signals given forth from the image intensifiercamera means 20 are impressed on a color television monitor 23 wherethere is conducted field scanning, as shown in FIG. 2E, in the order ofthree colors of red (R), green (G) and blue (B), the video signalobtained during the time width Ar, of the first gate pulse is reproducedon the screen of said monitor 23 in the form of a red image, the videosignal obtained during the time width Ar of the second gate pulse in theform ofa green image and the video signal obtained during the time widthA! of the third gate pulse in the form of a blue image. Now let it beassumed that there are located, for example, as shown in FIG. 1, oneobject 24 within the first zone of distance Al two objects 25 and 26within the second zone A1 and two objects 27 and 28 within the thirdzone Al If there is projected on to said foreground objects a laserlight comprismg a series of pulses PL PL; and PL, shown in FIG. 23through the first optical means 15, then there will be brought back tothe image intensifier camera means 20 the pulses of an echo laser lightshown in FIG. 2F through the second optical means 22. The resultant echolaser light pulses are focused on the second optical means 22 to formthe corresponding optical images. Thus on the screen of the colortelevision monitor 23 there will be reproduced, as shown in FIG. 20, ared image of the object 24 located in the first or nearest zone ofdistance Al a green image of the objects 25 and 26 lying in the secondzone A1 and a blue image of the objects 27 and 28 positioned tn thefarthest zone A1 The pulse signals shown in FIG. 2A generated by thepulse generation circuit 14 are also used as color-changing signals insaid color television monitor 23.

Accordingly, when mounted, for example, on a sailing ship as describedin this embodiment, a foreground object locating device according to thepresent invention is capable of detecting the presence of objects suchas other vessels, rocks or wharves located ahead of its scheduled courseaccording to a predetermined classification of zones of distance asrelated to the sailing speed of the first mentioned device-carryingship, in the form distinguished by different colors, namely, bydesignating an object lying in the first or nearest zone of distance Alfor example, as that calling for close watch against collision, anotherobject lying in the second zone A1 as that requiring precaution andstill another object lying in the third zone Al as a safe one. In otherwords, the foreground object locating device of the present inventionenables the presence of objects within the nearest zone calling forimmediate attention against collision to appeal unfailingly morestrongly to the human feeling than is possible with, for example, aconventional monochrome or color television. This allows mostappropriate means for example, change of the scheduled course to betaken quickly in case danger is approaching, thereby prominentlyreducing the possibility of accidents such as collisions which haveheretofore often taken place.

Obviously, application of the locating device of the present tnventionto aircraft or rolling stock like a rail road train will displaysubstantially the same effect.

Further, if installed in a harbor or straits, the locating device of thepresent invention can distinguish ships sailing on a sea zone callingfor close match where there are hidden known shoals or rocks or anotherzone adjacent thereto requiring precaution or a safe zone beyond them byreproducing those ships on the screen of a color television monitor 23in the form of, for example, a red, green or blue image respectively.Suitable communication with ships traveling on the aforesaid sea zonesconcerning the results of observation is a very effective means forassuring their safe navigation. Also if set up in an airport or on ahillside, the present device similarly offers great advantage inallowing airplanes to make a safe flight. Particularly, the presentinvention uses a pulsated laser light in locating foreground objects, sothat its operation is substantially not affected even under unfavorableconditions only per mitting a limited field of vision, for example, inan atmosphere field with mists or fogs consisting of scattered gasparticles or at'night time, thus enabling foreground objects to bereliably detected, because their images are always reproduced in goodcondition.

FIG. 3 is a detailed representation of the various circuit sections ofthe locating device 11 shown in FIG. 1. With the pulse generationcircuit 14, there are practically presented difficulties in forming, asshown in FIG. 2C, three delay pulses P P and P having different lengthsof time delay by directly supplying the pulse delay circuit 17 with aseries of pulses P P and F shown in FIG. 4A which are generated by apulse generator 31 in the same form as those of FIG. 2A. To eliminatesaid difficulties, the group of pulses P P and P shown in FIG. 4A whichare generated, for example, by said pulse generator 31 of FIG. 3, arefirst supplied to a saw wave generator 32, so as to produce saw wavesignals S S S shown in FIG. 4B at each cycle equal to the threerepetitive periods TRs of said pulses P,, 1 and P (corresponding to thenumber of colors used in color television presentation). Each of saidsignals 5,, S S starts at the beginning of said cycle and stops at theend thereof.

To the output terminal of said wave generator 32 are connected inparallel three clippers 33a, 34a and 35a comprising such as tunneldiodes whose bias points bias 1, bias 2 and bias 3 are defined at threepositions having different potentials on each of the leading edges l l lof the saw wave signals 8,, S S which are spaced from each other by adistance corresponding to the same time interval as said repetitiveperiod Tr. To the output terminals of said clippers 33a, 34a and 35a areconnected in series differentiation circuits 36, 37 and 38 respectively.The aforementioned arrangement is desirable for a practical circuitdesign. Thus from the output terminal of the pulse generator 14, or inthis case from each of the terminals of said three differentiationcircuits 36, 37 and 38 is separately drawn out in a predeterminedsequence of time as shown in FIG. 4C each one of the group consisting ofthree pulses P P and P shown in FIG. 4A. Accordingly, there is a timedifference Tr between the two sequential ones ofthe three pulses givenforth from the terminals of said three differentiation circuits. Fromthe terminal of the same differentiation circuit is drawn out a pulse atan interval equal to 3 Trs. It will be apparent that the aforementionedclippers 33a, 34a and 35a may be replaced by three monostablemultivibrators 33b, 34b and 35b. Three separate sets of pulses shown inFIG. 4C which are drawn out of the terminals of three differentiationcircuits 33a, 34a and 35a or monostable multivibrators 33b, 34b and 3512are conducted to the delay circuit 17 comprising three correspondingdelay lines 39, 40 and 41 formed of, for example, a variable inductanceand capacitance, and converted, as shown in FIG. 4D, to three delaypulses P P and P having three different lengths of time delay t t and trespectively (see FIG. 2C). These converted pulses P P and P aresupplied to three corresponding monostable multivibrators 42, 43 and 44to be converted to three gate pulses having three different time widthsAh, At and A1 Said gate pulses having such three different lengths oftime delay and three different time widths are jointly introduced into agate pulser 45 and drawn out, as shown in FIG. 4E, in the form ofsignals obtained by rearranging all said pulses in a predeterminedsequence of time (see FIG. 4D). The resultant signals are supplied tothe gate terminal of an image intensifier tube 46 involved in the imageintensifier camera means consisting of said image intensifier tube 46combined with an image tube (such as image orthicon tube or imagevidicon tube) 47. When, therefore, pulses of an echo laser light shownin FIGS. 2F and 4F, converted to the corresponding optical images onaforesaid second optical means 22 are brought into said imageintensifier tube 46, they produce the light pulse images shown in FIGS.2G and 4G, as the gate pulses shown in FIG. 4E are supplied. Said outputimage pulses from the image intensifier tube 46 are conducted to theimage orthicon tube 47 to be converted to video signals shown in FIG.4H. The image intensifier camera means 20 may consist of an image tubewhich has an image intensifier section such as an image intensifierorthicon tube, instead of an image intensifier tube 46 combined with animage tube 47. Said video signals are supplied to the color televisionreceiver 51 of the color television monitor 23 consisting of threemonostable multivibrators 48, 49 and 50 combined with said colortelevision receiver 51. At this time said color television receiver 51is also supplied with color signals shown in FIG. 41 consisting of threered, green and blue colors (see FIG. 2E). These color signals areobtained by supplying three sets of pulse signals shown in FIG. 4C whichare drawn out of the terminals of the aforesaid three differentiationcircuits 36, 37 and 38 to the three separate monostable multivibrators48, 49 and 50 which are brought to an operable state when said pulsesignals are introduced so as to generate output pulses having a timewidth corresponding to one vertical scanning period (equal to a fieldscanning period) of said color television receiver 51. Further, a seriesof pulses P P and P shown in FIG. 4A which are generated by the pulsegenerator 31 are supplied as color-changing signals to said colortelevision receiver 51 and image orthicon tube 47. Accordingly, thereare reproduced on the screen of said color television receiver 51 videoimages corresponding to respective foreground objects located in theaforementioned zones of distance Al Al and Al in the form distinguishedby colors.

The foregoing description relates to the cases in all of which there wasconducted field scanning in succession. It will be apparent, however,that the object of the present invention may also be attained, forexample, by carrying out field scanning at the same time using the samenumber of image intensifier camera means as that of colors used in colortelevision presentation.

What is claimed is:

1. In a foreground object locating device comprising:

a. a pulse generation circuit for generating a series of pulses having apreset repetitive period;

b. a laser light generator( 13) for generating a laser light consistingof a series of pulses having the same repetitive period when triggeredby output pulses from said pulse generation circuit;

c. a first optical means (15) for projecting the output pulsated laserlight from said laser light generator in a predetermined direction witha desired coverage; a second optical means (22) for receiving a pulsatedecho laser light reflected from various foreground objects present inthe direction in which said pulsated laser light is initially projectedby said laser light generator and focusing optical images correspondingto the pulsated echo laser light; and,

e. a color television mechanism (23) including a screen for receivingthe optical images focused on said second optical means and displayingon the screen thereof video images corresponding to the respectiveoptical images representing said objects present in previouslyclassified distance zones in the form distinguished by different colors,

the improvement therein wherein,

f. said pulse generation circuit (31) includes a pulse generator (31)for generating a series of pulses having the same repetitive period asthat of the series of laser light pulses generated by said laser lightgenerator;

g. a saw wave generator coupled to said pulse generator for receivingoutput pulses from said pulse generator to generate saw wave signalshaving substantially the same period as that which is covered by a setof pulses having the same number as that of the colors used in colortelevision presentation;

h. a plurality of juxtaposed clippers (33a etc.) coupled for receivingoutput saw wave signals from said saw wave generator, the bias points ofsaid clippers being defined at plural positions having differentpotentials on the leading edge of each of said saw wave signals whichare spaced from each other by a distance corresponding to substantiallythe same time interval as the repetitive period of said series lightpulses; and,

101027 nsis l. a plurality of differentiation circuits (36 etc.)connected in series to the output terminal of each ofsaid clippers.

2. In a foreground object locating device comprising a pulse generationcircuit for generating a series of pulses having a preset repetitiveperiod, a laser light generator for generating a laser light consistingof a series of pulses having the same repetitive period when triggeredby output pulses from said pulse generation circuit, a first opticalmeans for projecting the output pulsated laser light from said laserlight generator tn a predetermined direction with a desired coverage, asecond optical means for receiving a pulsated echo laser light reflectedfrom various foreground objects present in the direction in which saidpulsated laser light is initially projected by said laser lightgenerator and focusing optical images corresponding to the pulsated echolaser light. and a color television mechanism including a screen forreceiving the optical images focused on said second optical means anddisplaying on the screen video images corresponding to the respectiveoptical images representing said objects present in the previouslyclassified distance zones in the form distinguished by different colors,the improvement therein wherein said pulse generation circuit includes apulse generator for generating a series of pulses having the samerepetitive period as that ofthe 581165 laser light pulses generated bysaid laser light generator; a saw wave generator coupled to said pulsegenerator for receiving output pulses from said pulse generator togenerate saw wave signals having substantially the same period as thatwhich is covered by a set of pulses having the same number as that ofthe colors used in color television presentation; a plurality ofjuxtaposed monostable multivibrators for receiving output saw wavesignals from said saw wave generator, the bias points of said monostablemultivibrators (48. 49. 50) being defined at plural positions havingdifferent potentials on the leading edge of each of said saw wavesignals which are spaced from each other by a distance corresponding tosubstantially the same time interval as the repetitive period of saidteries laser light pulses; and

lit plurality of differentiation circuits connected in series to theoutput terminal of each of said monostable multivibrators.

i in a foreground object locating device comprising a pulse generationcircuit for generating a series of pulses having a preset repetitiveperiod, a laser light generator for generating a laser light consistingof a series of pulses having the same repetitive period when triggeredby output pulses from said pulse generation circuit, a first opticalmeans for projecting the output pulsated laser light from said laserlight generator in a predetermined direction with a desired coverage, asecond optical means for receiving a pulsated echo laser light reflectedfrom various foreground objects present in the direction in which saidpulsated laser light is initially projected by said laser lightgenerator and focusing optical images corresponding to the pulsated echolaser light, and a color television mechanism including a screen forreceiving the optical tmages focused on said second optical means anddisplaying on the screen video images corresponding to the respectivepptical images representing said objects present in previouslyclassified distance zones in the form distinguished by different colors,the improvement therein wherein said color television mechanism includesa laser light monitor for converting part of the pulsated laser lightgenerated by said laser light generator to the corresponding electricpulses by photodetector; a plurality of delay circuits (39, 40, 41) forreceiving the corresponding output electric pulses from said laser lightmonitor llmd providing plural time delays required for the individuallaser light pulses constituting each set thereof to pass through thecorresponding delay distance zones roundtrip; a plurality of gate pulsegeneration circuits for converting the plural time delayed pulses fromsaid delay circuits to plural gate pulses having time widthscorresponding to the respective distance tones associated with theindividual laser light pulses constituting said each set thereof; animage intensifier camera t46) means brought to an operable state only ifit is supplied with the gate pulses from said gate pulse generationcircuits to receive the optical images focused on said second opticalmeans and converting them into the corresponding video signals; and acolor television monitor for receiving output video signals from saidimage intensifier camera means to display on the screen video images inresponse to the output video signals in said distinguished colors, usingoutput pulses from said pulse generation circuit as its color changingsignals.

4. The locating device according to claim 1, wherein said colortelevision mechanism comprises a plurality of delay circuits forreceiving output pulses from said corresponding differentiation circuitsand providing plural time delays required for the individual laser lightpulses constituting said each set hereof to pass through thecorresponding distance zones roundtrip; a plurality of gate pulsegeneration circuits for converting the the plural time delayed pulsesfrom said delay circuits to plural gate pulses having time widthscorresponding to the respective distance zones associated with theindividual laser light pulses constituting said each set thereof; animage intensifier camera means brought to an operable state only if itis supplied with the gate pulses from said gate pulse generationcircuits to receive the optical images focused on said second opticalmeans and convert them into the corresponding video signals; and a colortelevision monitor for receiving output video signals from said imageintensifier camera means to display on the screen video images inresponse to the output video signals in said distinguished colors, usingoutput pulses from said differentiation circuits as its color changingsignals.

5. The locating device according to claim 2, wherein said colortelevision mechanism comprises a plurality of delay cirsum for receivingoutput pulses from said corresponding differentiation circuits andproviding plural time delays required for the individual laser lightpulses constituting said each set thereof to pass through thecorresponding distance zones roundtrip; a plurality of gate pulsegeneration circuits for converting the plural time delayed pulses fromsaid delay circuits to plural gate pulses having time widthscorresponding to the respective distance zones associated with theindividual laser light pulses constituting said each set thereof; animage intensifier camera means brought to an operable state only if itis supplied with the gate pulses from said gate pulse generationcircuits to receive the optical images focused on said second opticalmeans and convert them into the corresponding video signals; and a colortelevision monitor for receiving output video signals from said imageintensifier camera means to display on the screen video images inresponse to the output video signals in said distinguished colors, usingoutput pulses from said differentiation circuits as its color changingsignals.

6. The locating device according to claim 4, wherein said gate pulsegeneration circuits comprise a plurality of monostable multivibrators(42, 43, 44) for receiving output pulses from said corresponding delaycircuits and converting them into pulses having time widthscorresponding to said respective distance zones, and a gate pulser intowhich there are jointly introduced output pulses from said monostablemultivibrators and from the output terminal of which there are drawn outgate pulses rearranged in a predetermined sequence of time.

'i'i The locating device according to claim 5, wherein said gate pulsegeneration circuits comprise a plurality of monostable multivibrators(42, 43, 44) for receiving output pulses from said corresponding delaycircuits and converting them into pulses having time widthscorresponding to said respective distance zones, and a gate pulser intowhich there are ointly introduced output pulses from said monostablemultivibrators and from the output terminal of which there are drawn outgate pulses rearranged in a predetermined sequence of time.

8. The locating device according to claim 4, wherein said colortelevision monitor comprises a plurality of monostable multivibratorsfor receiving output pulses from said corresponding differentiationcircuits to form a set of color signals constituting one frame for colortelevision scan, each of said color signals having a pulse widthequivalent to one signals constituting one frame for color televisionscan, each of said color signals having a pulse width equivalent to onevertical scanning period of television, and a color television receiversupplied with output color signals from said monostable multivibratorsand output video signals from said image intensifier camera means todisplay on the screen video images representing said objects present inclassified distance zones under control of output pulses from said pulsegenerator in said distinguished colors.

101027 nsi':

1. In a foreground object locating device comprising: a. a pulsegeneration circuit for generating a series of pulses having a presetrepetitive period; b. a laser light generator(13) for generating a laserlight consisting of a series of pulses having the same repetitive periodwhen triggered by output pulses from said pulse generation circuit; c. afirst optical means (15) for projecting the output pulsated laser lightfrom said laser light generator in a predetermined direction with adesired coverage; d. a second optical means (22) for receiving apulsated echo laser light reflected from various foreground objectspresent in the direction in which said pulsated laser light is initiallyprojected by said laser light generator and focusing optical imagescorresponding to the pulsated echo laser light; and, e. a colortelevision mechanism (23) including a screen for receiving the opticalimages focused on said second optical means and displaying on the screenthereof video images corresponding to the respective optical imagesrepresenting said objects present in previously classified distancezones in the form distinguished by different colors, the improvementtherein wherein, f. said pulse generation circuit (31) includes a pulsegenerator (31) for generating a series of pulses having the samerepetitive period as that of the series of laser light pulses generatedby said laser light generator; g. a saw wave generator coupled to saidpulse generator for receiving output pulses from said pulse generator togenerate saw wave signals having substantially the same period as thatwhich is covered by a set of pulses having the same number as that ofthe colors used in color television presentation; h. a plurality ofjuxtaposed clippers (33a etc.) coupled for receiving output saw wavesignals from said saw wave generator, the bias points of said clippersbeing defined at plural positions having different potentials on theleading edge of each of said saw wave signals which are spaced from eachother by a distance corresponding to substantially the same timeinterval as the repetitive period of said series light pulses; and, i. aplurality of differentiation circuits (36 etc.) connected in series tothe output terminal of each of said clippers.
 2. In a foreground objectlocating device comprising a pulse generation circuit for generating aseries of pulses having a preset repetitive period, a laser lightgenerator for generating a laser light consisting of a series of pulseshaving the same repetitive period when triggered by output pulses fromsaid pulse generation circuit, a first optical means for projecting theoutput pulsated laser light from said laser light generator in apredetermined direction with a desired coverage, a second optical meansfor receiving a pulsated echo laser light reflected from variousforeground objects present in the direction in which said pulsated laserlight is initially projected by said laser light generator and focusingoptical images corresponding to the pulsated echo laser light, and acolor television mechanism including a screen for receiving the opticalimages focused on said second optical means and displaying on the screenvideo images corresponding to the respective optical images representingsaid objects present in the previously classified distance zones in theform distinguished by different colors, the improvement therein whereinsaid pulse generation circuit includes a pulse generator for generatinga series of pulses having the same repetitive period as that of theseries laser light pulses generated by said laser light generator; a sawwave generator coupled to said pulse generator for receiving outputpulses from said pulse generator to generate saw wave signals havingsubstantially the same period as that which is covered by a set ofpulses having the same number as that of the colors used in colortelevision presentation; a plurality of juxtaposed monostablemultivibrators for receiving output saw wave signals from said saw wavegenerator, the bias points of said monostable multivibrators (48, 49,50) being defined at plural positions having different potentials on theleading edge of each of said saw wave signals which are spaced from eachother by a distance corresponding to substantially the same timeinterval as the repetitive period of said series laser light pulses; anda plurality of differentiation circuits connected in series to theoutput terminal of each of said monostable multivibrators.
 3. In aforeground object locating device comprising a pulse generation circuitfor generating a series of pulses having a preset repetitive period, alaser light generator for generating a laser light consisting of aseries of pulses having the same repetitive period when triggered byoutput pulses from said pulse generation circuit, a first optical meansfor projecting the output pulsated laser light from said laser lightgenerator in a predetermined direction with a desired coverage, a secondoptical means for receiving a pulsated echo laser light reflected fromvarious foreground objects present in the direction in which saidpulsated laser light is initially projected by said laser lightgenerator and focusing optical images corresponding to the pulsated echolaser light, and a color television mechanism including a screen forreceiving the optical images focused on said second optical means anddisplaying on the screen video imaGes corresponding to the respectiveoptical images representing said objects present in previouslyclassified distance zones in the form distinguished by different colors,the improvement therein wherein said color television mechanism includesa laser light monitor for converting part of the pulsated laser lightgenerated by said laser light generator to the corresponding electricpulses by photodetector; a plurality of delay circuits (39, 40, 41) forreceiving the corresponding output electric pulses from said laser lightmonitor and providing plural time delays required for the individuallaser light pulses constituting each set thereof to pass through thecorresponding delay distance zones roundtrip; a plurality of gate pulsegeneration circuits for converting the plural time delayed pulses fromsaid delay circuits to plural gate pulses having time widthscorresponding to the respective distance zones associated with theindividual laser light pulses constituting said each set thereof; animage intensifier camera (46) means brought to an operable state only ifit is supplied with the gate pulses from said gate pulse generationcircuits to receive the optical images focused on said second opticalmeans and converting them into the corresponding video signals; and acolor television monitor for receiving output video signals from saidimage intensifier camera means to display on the screen video images inresponse to the output video signals in said distinguished colors, usingoutput pulses from said pulse generation circuit as its color changingsignals.
 4. The locating device according to claim 1, wherein said colortelevision mechanism comprises a plurality of delay circuits forreceiving output pulses from said corresponding differentiation circuitsand providing plural time delays required for the individual laser lightpulses constituting said each set hereof to pass through thecorresponding distance zones roundtrip; a plurality of gate pulsegeneration circuits for converting the the plural time delayed pulsesfrom said delay circuits to plural gate pulses having time widthscorresponding to the respective distance zones associated with theindividual laser light pulses constituting said each set thereof; animage intensifier camera means brought to an operable state only if itis supplied with the gate pulses from said gate pulse generationcircuits to receive the optical images focused on said second opticalmeans and convert them into the corresponding video signals; and a colortelevision monitor for receiving output video signals from said imageintensifier camera means to display on the screen video images inresponse to the output video signals in said distinguished colors, usingoutput pulses from said differentiation circuits as its color changingsignals.
 5. The locating device according to claim 2, wherein said colortelevision mechanism comprises a plurality of delay circuits forreceiving output pulses from said corresponding differentiation circuitsand providing plural time delays required for the individual laser lightpulses constituting said each set thereof to pass through thecorresponding distance zones roundtrip; a plurality of gate pulsegeneration circuits for converting the plural time delayed pulses fromsaid delay circuits to plural gate pulses having time widthscorresponding to the respective distance zones associated with theindividual laser light pulses constituting said each set thereof; animage intensifier camera means brought to an operable state only if itis supplied with the gate pulses from said gate pulse generationcircuits to receive the optical images focused on said second opticalmeans and convert them into the corresponding video signals; and a colortelevision monitor for receiving output video signals from said imageintensifier camera means to display on the screen video images inresponse to the output video signals in said distinguished colors, usingoutput pulses from said differentiation circuits as its color chaNgingsignals.
 6. The locating device according to claim 4, wherein said gatepulse generation circuits comprise a plurality of monostablemultivibrators (42, 43, 44) for receiving output pulses from saidcorresponding delay circuits and converting them into pulses having timewidths corresponding to said respective distance zones, and a gatepulser into which there are jointly introduced output pulses from saidmonostable multivibrators and from the output terminal of which thereare drawn out gate pulses rearranged in a predetermined sequence oftime.
 7. The locating device according to claim 5, wherein said gatepulse generation circuits comprise a plurality of monostablemultivibrators (42, 43, 44) for receiving output pulses from saidcorresponding delay circuits and converting them into pulses having timewidths corresponding to said respective distance zones, and a gatepulser into which there are jointly introduced output pulses from saidmonostable multivibrators and from the output terminal of which thereare drawn out gate pulses rearranged in a predetermined sequence oftime.
 8. The locating device according to claim 4, wherein said colortelevision monitor comprises a plurality of monostable multivibratorsfor receiving output pulses from said corresponding differentiationcircuits to form a set of color signals constituting one frame for colortelevision scan, each of said color signals having a pulse widthequivalent to one vertical scanning period of television, and a colortelevision receiver supplied with output color signals from saidmonostable multivibrators and output video signals from said imageintensifier camera means to display on the screen video imagesrepresenting said objects present in classified distance zones undercontrol of output pulses from said pulse generator in said distinguishedcolors.
 9. The locating device according to claim 5, wherein said colortelevision monitor comprises a plurality of monostable multivibratorsfor receiving output pulses from said corresponding differentiationcircuits to form a set of color signals constituting one frame for colortelevision scan, each of said color signals having a pulse widthequivalent to one vertical scanning period of television, and a colortelevision receiver supplied with output color signals from saidmonostable multivibrators and output video signals from said imageintensifier camera means to display on the screen video imagesrepresenting said objects present in classified distance zones undercontrol of output pulses from said pulse generator in said distinguishedcolors.